This application relates to emergency oxygen supply systems, and more particularly to a system that is automatically actuated to supply oxygen when removed from a storage position.
Emergency oxygen supply systems are known in which oxygen flow from an oxygen tank to an oxygen mask is blocked by a valve maintained in a closed position by a pin. Upon removal of the pin, the valve moves to an open position and oxygen may flow from the tank to the mask. A system as described above is disclosed in U.S. Pat. No. 4,802,472.
Other prior art oxygen supply systems have similar pins that can be pulled to force a perforator into a seal on an oxygen tank. Once the seal is perforated, oxygen can flow from the tank to an oxygen supply point, such as a mask. Systems as described above are disclosed in U.S. Pat. Nos. 2,852,023 and 4,805,802.
These prior art systems are stored in locations where an emergency oxygen supply may become necessary, and the tanks must maintain an adequate quantity of oxygen over a long period of time, thus, flow is normally blocked. At the same time, it is essential in an emergency situation that the flow from an oxygen tank to the mask be actuated quickly. The pins disclosed in the prior art have attempted to provide this quick actuation. The prior art systems have been deficient, however, in some respects.
One problem with the prior art systems is that the emergency actuation of oxygen flow normally requires a two-step procedure. The systems are maintained in some storage position; an operator must first remove the system from this storage position, and then locate and remove the pin to actuate flow. Situations which require an emergency oxygen supply do not lend themselves to careful study of a system in order to actuate it. Prior art systems that require removal from a storage position, then searching for a pin that must be removed, require excessive time. In a situation where emergency flow of oxygen is necessary, the elimination of one of these two steps would be desirable.
Most oxygen supply systems also require some sort of regulator valve to prevent overly high pressures from reaching an oxygen supply mask. In the prior art systems the valves which block flow from the tank to the mask do not also regulate the pressure supplied to the mask. It would be desirable, from a simplicity of manufacture standpoint, as well as to remove unnecessary obstructions in the flow path, to achieve both of these valving functions with a single valve.
It is therefore an object of the present invention to disclose an emergency oxygen supply system in which the flow of oxygen from a tank to a mask is actuated with a one-step procedure. In addition, it is an object of the present invention to disclose an emergency oxygen supply system in which the flow of oxygen from a tank to a mask is selectively blocked, and the pressure supplied from the tank to the mask is also regulated, through a single valve.